diff include/PRU.h @ 307:ff5f346a293e prerelease

Changed BelaContext fields to be const where appropriate; there's now an InternalBelaContext used for setting the values within the core code. These need to stay aligned.

--- a/include/PRU.h	Fri May 27 18:00:57 2016 +0100
+++ b/include/PRU.h	Fri May 27 18:12:15 2016 +0100
@@ -12,6 +12,101 @@
 #include <native/intr.h>
 #include "../include/Bela.h"
 
+/**
+ * Internal version of the BelaContext struct which does not have const
+ * elements, so it can be modified by the code. When it's passed to the user
+ * code, it is typecast to the standard BelaContext.
+ *
+ * Important: make sure this retains the same structure as BelaContext!
+ */
+typedef struct {
+	/// \brief Buffer holding audio input samples
+	///
+	/// This buffer may be in either interleaved or non-interleaved format,
+	/// depending on the contents of the BelaInitSettings structure.
+	/// \b Note: this element is available in render() only.
+	float *audioIn;
+
+	/// \brief Buffer holding audio output samples
+	///
+	/// This buffer may be in either interleaved or non-interleaved format,
+	/// depending on the contents of the BelaInitSettings structure.
+	/// \b Note: this element is available in render() only.
+	float *audioOut;
+
+	/// \brief Buffer holding analog input samples
+	///
+	/// This buffer may be in either interleaved or non-interleaved format,
+	/// depending on the contents of the BelaInitSettings structure.
+	/// \b Note: this element is available in render() only.
+	float *analogIn;
+
+	/// \brief Buffer holding analog output samples
+	///
+	/// This buffer may be in either interleaved or non-interleaved format,
+	/// depending on the contents of the BelaInitSettings structure.
+	/// \b Note: this element is available in render() only.
+	float *analogOut;
+
+	/// \brief Buffer holding digital input/output samples
+	///
+	/// \b Note: this element is available in render() only.
+	uint32_t *digital;
+
+	/// Number of audio frames per period
+	uint32_t audioFrames;
+	/// Number of audio channels (currently always 2)
+	uint32_t audioChannels;
+	/// Audio sample rate in Hz (currently always 44100.0)
+	float audioSampleRate;
+
+	/// \brief Number of analog frames per period
+	///
+	/// This will be 0 if analog I/O is disabled.
+	uint32_t analogFrames;
+
+	/// \brief Number of analog channels
+	///
+	/// This could take a value of 8, 4 or 2. This will be 0 if analog I/O is disabled.
+	uint32_t analogChannels;
+
+	/// \brief Analog sample rate in Hz
+	///
+	/// The analog sample rate depends on the number of analog channels used. If
+	/// 8 channels are used, the sample rate is 22050. If 4 channels are used, the sample
+	/// rate is 44100. If 2 channels are used, the sample rate is 88200. If analog I/O
+	/// is disabled, the sample rate is 0.
+	float analogSampleRate;
+
+	/// Number of digital frames per period
+	uint32_t digitalFrames;
+	/// \brief Number of digital channels
+	///
+	/// Currently this will always be 16, unless digital I/O is disabled, in which case it will be 0.
+	uint32_t digitalChannels;
+	/// Digital sample rate in Hz (currently always 44100.0)
+	float digitalSampleRate;
+
+	/// \brief Number of elapsed audio samples since the start of rendering.
+	///
+	/// This holds the total number of audio samples as of the beginning of the current period. To
+	/// find the current number of analog or digital samples elapsed, multiply by the ratio of the
+	/// sample rates (e.g. half the number of analog samples will have elapsed if the analog sample
+	/// rate is 22050).
+	uint64_t audioSampleCount;
+
+	/// \brief Other audio/sensor settings
+	///
+	/// Binary combination of flags including:
+	///
+	/// BELA_FLAG_INTERLEAVED: indicates the audio and analog buffers are interleaved
+	///
+	/// BELA_FLAG_ANALOG_OUTPUTS_PERSIST: indicates that writes to the analog outputs will
+	/// persist for future frames. If not set, writes affect one frame only.
+	uint32_t flags;
+} InternalBelaContext;
+
+
 class PRU
 {
 private:
@@ -23,7 +118,7 @@
 
 public:
 	// Constructor
-	PRU(BelaContext *input_context);
+	PRU(InternalBelaContext *input_context);
 
 	// Destructor
 	~PRU();
@@ -56,7 +151,7 @@
 	void clearGPIOTestPin();
 
 private:
-	BelaContext *context;	// Overall settings
+	InternalBelaContext *context;	// Overall settings
 
 	int pru_number;		// Which PRU we use
 	bool running;		// Whether the PRU is running